Hoback

Hi, I've just had my SAS replaced (211-545-01-16) but after driving for a few minutes the "ESP inoperative" message comes back on. I've tried resetting it by turning lock to lock but that didn't help. Does a new SAS require calibration?

cetialpha5

Did you scan it with a scan tool that does MB specific codes? I did mine and there was no calibration needed. But when I scanned it, it mentioned the steering angle sensor had a problem. You may have jumped the gun. Could be a brake light switch or a wheel speed sensor or the yaw sensor in addition to the steering angel sensor. Get a code reader that does MB specific codes, they're not that much money like this one, Autel AP200, about $63.

Hoback

It was scanned by one of our technicians (I work for a BMW Dealer 😁 haha) before replacing the sensor. He could not get any readings from it. When he changed it yesterday and scanned the car again he could see that the sensor was working.

Before the ESP light would come on almost immediately after you turn the wheel. Now you can drive the car for a while with no warning whatsoever.

bbirdwell

Aftermarket tires? Inflation pressure? Any work on the corners that might have disturbed a sensor?

FWIW, the two times I used the spare tire on my W211 (both times right rear), in each case it threw a check engine light and I received ESP and ABS codes plus others. Check engine light cleared after reinstalling a replacement tire but I had to go into the system to clear multiple stored codes.

cetialpha5

Brake light switch and one of the wheel speed sensors going bad is also common. Those should come up when you get it scanned again. No communication with the steering angle sensor is also one of the error codes that tells you it needs to be replaced. Either a bad one or you've got a couple other things wrong with it. Sounds like you need a better scanner.

Hoback

All done! The light’s finally gone. Turned out the infamous brake light switch was also faulty. Thanks everyone for your help. Much appreciated.